Local area network free data movement

ABSTRACT

Systems and methods for backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN). The systems and methods include receiving a snapshot of a virtual machine (VM), the VM being associated with a VM datastore disk, which is further associated with a unique ID. The unique ID associated with the VM datastore disk is compared with a unique ID associated with a disk available on the computing device. When the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device, the disk on the computing device with the matching unique ID is opened for reading, and data from the opened disk is copied to a copy data storage pool over a storage area network.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) to U.S. application Ser. No. 61/940,163, entitled “LOCAL AREA NETWORK FREE DATA MOVEMENT”, filed Feb. 14, 2014, the contents of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to data management, specifically to local area network (LAN) free data movement.

BACKGROUND

Traditionally, LAN Free Data movement is only available when the storage for a virtual machine being backed up is in an inband datastore. LAN-based backup can be much slower than LAN Free-based backup, for example, storage area network (SAN) based backup.

SUMMARY OF THE INVENTION

The techniques described herein can provide a sideband feature that can allow LAN-free data capture or backup of Virtual Machines (VMs) or other datastores even though the VM or datastore is not inband.

The disclosed subject matter includes a computerized method of backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN). The method includes receiving, by a computing device, a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID. The method includes comparing, by the computing device, the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device. The method includes determining, by the computing device, the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device. The method includes opening for reading, by the computing device, the disk on the computing device with the matching unique ID. The method includes copying, by the computing device, data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN).

The disclosed subject matter includes computing system for backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN). The computing system includes a processor and a memory coupled to the processor and including computer-readable instructions that, when executed by the processor, cause the processor to receive a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID. The computer-readable instructions cause the processor to compare the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device. The computer-readable instructions cause the processor to determine the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device. The computer-readable instructions cause the processor to open the disk on the computing device with the matching unique ID. The computer-readable instructions cause the processor to copy data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN).

The disclosed subject matter includes a non-transitory computer readable medium having executable instructions operable to cause an apparatus to receive a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID. The executable instructions are operable to cause the apparatus to compare the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device. The executable instructions are operable to cause the apparatus to determine the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device. The executable instructions are operable to cause the apparatus to open the disk on the computing device with the matching unique ID. The executable instructions are operable to cause the apparatus to copy data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN).

BRIEF DESCRIPTION OF FIGURES

Various objectives, features, and advantages of the disclosed subject matter can be more fully appreciated with reference to the following detailed description of the disclosed subject matter when considered in connection with the following drawings, in which like reference numerals identify like elements.

FIG. 1 illustrates the types of storage in a Virtualization Hypervisor environment, according to some embodiments of the present disclosure.

FIG. 2 illustrates LAN Based and LAN Free Data Movement, according to some embodiments of the present disclosure.

FIG. 3 illustrates LAN Based Data Movement from a SAN Datastore.

FIG. 4 illustrates the Zoning and Mapping requirements for LAN Free Data Movement from a SAN Based Datastore, according to some embodiments of the present disclosure.

FIG. 5 illustrates the configuration for SAN based Data Movement for a SAN based datastore, according to some embodiments of the present disclosure.

FIG. 6 illustrates how Copy Management Server uses Managed Disks and Virtual Disks, according to some embodiments of the present disclosure.

FIG. 7 shows the flowchart of the LAN free backup of the SAN based LUN, according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The present disclosure relates to U.S. patent application Ser. No. 13/920,981, filed on Jun. 18, 2013, entitled “System and method for incrementally backing up out-of-band data,” which is hereby incorporated by reference herein in its entirety.

In the following description, numerous specific details are set forth regarding the systems and methods of the disclosed subject matter and the environment in which such systems and methods may operate, etc., in order to provide a thorough understanding of the disclosed subject matter. It will be apparent to one skilled in the art, however, that the disclosed subject matter may be practiced without such specific details, and that certain features, which are well known in the art, are not described in detail in order to avoid unnecessary complication of the disclosed subject matter. In addition, it will be understood that the embodiments provided below are exemplary, and that it is contemplated that there are other systems and methods that are within the scope of the disclosed subject matter.

In some embodiments, when capturing the data of a Virtual Machine, a backup application may need to create a snapshot of the virtual image, and then copy the data out of the snapshot either over the local area network (LAN) or over the storage area network (SAN) into copy data storage. At the end of the backup, the snapshot can be deleted.

Previously if the datastore were in-band, that is, the logical unit number (LUN) containing the data were presented to the VMware hypervisor by the copy data server, then the backup was done over the SAN (i.e., a LAN-free backup). In any other datastore configuration, the data movement was over the LAN.

In some embodiments, a sideband feature as described herein can allow LAN free data capture or backup of Virtual Machines (VMs) when Datastores that the Virtual Machines reside on use unique identifiers (e.g., a FiberChannel LUN (FC-Based LUN)). In some embodiments, LAN free data movement can be performed even though the datastore is not inband. LAN free backup is usually faster, with less impact on other systems in a data center, and more secure. In some embodiments, data movement can be performed over a SAN to provide for SAN-based data movement even when the datastore is not inband. Such techniques can be used, for example, by systems that generate copy data, where the system may have both in-band and out-of-band disks. The techniques can be used to take an out-of-band disk and allow access to the disk from the copy data system, such as by making an out-of-band disk that can copy of the SAN.

In some embodiments, in any configuration where the datastore resides on an FC-based LUN, LAN free data movement is enabled. In some embodiments, the LUN containing the datastore can be zoned to the Copy Data Server.

FIG. 1 illustrates the types of storage in a Virtualization Hypervisor environment, according to some embodiments of the present disclosure. FIG. 1 depicts a Virtualization Hypervisor 3501, a Copy Data Management Server 3509, a Non-SAN Datastore 3503, a SAN Datastore 3505, an inband Datastore 3506, and a Copy Data Storage 3508. FIG. 1 further depicts Virtualization Hypervisor 3501 connected to Copy Data Management Server 3509 by a Fiber Channel (FC) or Internet Small Computer System Interface (iSCSI) connection 3510, Virtualization Hypervisor 3501 connected to SAN Datastore 3505 by an FC or iSCSI connection 3504, and Virtualization Hypervisor 3501 connected to Non-SAN Datastore 3503 by a Serial ATA (SATA) or Network Attached Storage (NAS) connection 3502. FIG. 1 also depicts Copy Data Management Server 3509 connected to inband Datastore 3506 by an FC or iSCSI connection 3507, and Copy Data Management Server 3509 connected to Copy Data Storage 3508 by an FC or iSCSI connection 3511.

In some embodiments, Virtualization Hypervisor 3501 can be an ESX Host from VMware. Virtualization Hypervisor 3501 can store its data, including the configuration and storage for the guest operating systems of virtual machines in datastores 3503, 3505 and 3506.

In some embodiments, one type of datastore can be non-SAN datastore 3503. Non-SAN datastore 3503 can reside on an internal drive within the Hypervisor frame, or in an external Network Attached Storage (NAS) Share. The connection between non-SAN datastore and Virtualization Hypervisor 3501 can be an SATA or an NAS protocol 3502.

In some embodiments, another type of datastore can be SAN datastore 3505. SAN datastore 3505 can reside in an external array, and can be connected to Hypervisor through iSCSI or FC 3504.

In some embodiments, another type of datastore can be inband datastore 3506. Inband datastore 3506 can reside in an external array which can be presented to Copy Management Server 3509, over an iSCSI or Fibrechannel connection 3507, which Copy Management Server 3509 can present to Virtualization Hypervisor 3501.

In some embodiments, additional data storage capacity 3508 can be made available to Copy Management Server 3509. Copy Management Server 3509 can use this additional storage for various copy storage pools.

Previously, LAN-free data movement was only available when the storage for the virtual machine being backed up was in the inband datastore 3506. The sideband feature, as described herein, enables the LAN free backup of SAN Datastore 3505.

FIG. 2 illustrates LAN-based and LAN-free data movement, according to some embodiments of the present disclosure. FIG. 2 depicts a SAN connection 3512 and Network connection 3513 between Virtualization Hypervisor 3501 and Copy Management Data Server 3509. The Virtualization Hypervisor 3501 is also in communication with a non-SAN datastore 3503 and SAN datastore 3505. The Copy Data Management Server 3509 is in communication with inband datastore 3506 and copy data storage 3508.

In some embodiments, there can be a SAN connection 3512 between Virtualization Hypervisor 3501 and Copy Data Management Server. There can also be a Network Connection 3513 between Virtualization Hypervisor 3501 and Copy Data Management Server 3509.

Dashed Arrow 3514 shows a path taken by LAN Based Data Movement when backing up a VM that has its storage in Non-SAN Datastore 3503. The data can be read by Virtualization Hypervisor 3501 and then sent over the Network or LAN 3513 to Copy Data Management Server 3509. Copy Data Management Server can write the data to Copy Data Storage 3508. The Data travels over the LAN, and can be considered LAN Based movement.

Dotted Arrow 3515 shows a path taken by LAN Free Data Movement when backing up a VM that has its storage on inband Datastore 3506. The data can be read by Copy Data Management Server 3509 over the SAN and written to Copy Data Storage 3508. The data does not travel over the LAN, and therefore can be considered LAN Free Data movement.

FIG. 3 illustrates LAN Based Data Movement from a SAN Datastore. FIG. 3 depicts a SAN connection 3512 and Network connection 3513 between Virtualization Hypervisor 3501 and Copy Management Data Server 3509. The Virtualization Hypervisor 3501 is also in communication with a non-SAN datastore 3503 and SAN datastore 3505. The Copy Data Management Server 3509 is in communication with inband datastore 3506 and copy data storage 3508.

Without the zoning process, as described herein, Copy Data Management Server 3509, can be unaware that the datastore containing the virtual machine files can be accessed. Copy Data Management Server 3509 can use a hypervisor's vendor provided application programming interface to read the data over the network, which takes a path from SAN Based Storage 3505 through Virtualization Hypervisor, 3501 over the LAN interface 3513, to Copy Management Server 3509. This results in LAN Based data movement for a SAN based datastore, 3517.

FIG. 4 illustrates the Zoning and Mapping requirements for LAN Free Data Movement from a SAN Based Datastore, according to some embodiments of the present disclosure. FIG. 4 depicts a SAN connection 3512 and Network connection 3513 between Virtualization Hypervisor 3501 and Copy Management Data Server 3509. The Virtualization Hypervisor 3501 is also in communication with a non-SAN datastore 3503 and SAN datastore 3505. The Copy Data Management Server 3509 is in communication with inband datastore 3506 and copy data storage 3508. FIG. 4 further depicts a SAN technology connection (e.g., FC or iSCSI Connection) 3516 between SAN Datastore 3505 and Copy Data Management Server 3509.

In some embodiments, SAN Based Datastore 3505 can be zoned to Copy Data Management Server 3509, so that Copy Data Management Server 3509 can directly read data from SAN Datastore 3505 over a Fibrechannel or iSCSI SAN connection 3516.

In some embodiments, this zoning can be accomplished by configuring SAN switches so that SAN Datastore 3505 is visible to Copy Data Management Server 3509. In some embodiments, storage and hosts can be connected by cables to SAN switches. The SAN switches can be configured to present certain disks to certain hosts, and other disks to other hosts. In some embodiments, configuring a SAN switch comprises taking an existing configuration of a SAN switch, which allows the datastore disk to be seen by one or more hypervisor hosts, and modifying it to allow Copy Management Server 3509 to also see the disk. The array containing the datastore can be configured to map the disks making up the datastore to Copy Management Server 3509.

In some embodiments, Copy Management Server 3509 can see this zoned and mapped disk as a Managed disk. A managed disk is a disk where the server can control the inputs and outputs of the disk.

FIG. 5 illustrates the configuration for SAN based Data Movement for a SAN based datastore, according to some embodiments of the present disclosure. FIG. 5 depicts a SAN connection 3512 and Network connection 3513 between Virtualization Hypervisor 3501 and Copy Management Data Server 3509. The Virtualization Hypervisor 3501 is also in communication with a non-SAN datastore 3503 and SAN datastore 3505. The Copy Data Management Server 3509 is in communication with inband datastore 3506 and copy data storage 3508. FIG. 5 further depicts a SAN technology connection (e.g., FC or iSCSI Connection) 3516 between SAN Datastore 3505 and Copy Data Management Server 3509.

In some embodiments, a SAN based datastore 3505 can be zoned in accordance to the requirements of Copy Management Server 3509. In some embodiments, Data Movement can occur by Copy Data Management Server 3509 recognizing that characteristics (e.g., SCSI ID) of one of the disks visible to it over the SAN is the same as the characteristics (e.g., SCSI ID) of the disk of SAN Datastore 3505 as reported by Virtualization Hypervisor 3501. In some embodiments, each disk can have a unique characteristic that differentiates the disk from other disks. Data Management Server 3505 can then use the characteristic (e.g., SCSI ID) to read the data directly from Copy Data Storage 3508 resulting in the path depicted by 3557, which is a LAN Free data movement path. While the connection 3516 between the SAN Datastore 3505 and the Copy Data Management Server 3509 is shown as a FibreChannel or iSCSI Connection, one of skill in the art can appreciate that the connection can use any SAN technologies, including those not illustrated in FIG. 5 such as Infiniband.

FIG. 6 illustrates how Copy Management Server uses Managed Disks and Virtual Disks, according to some embodiments of the present disclosure. FIG. 6 depicts the Virtualization Hypervisor 3501 and the Copy Management Data Server 3509. The Virtualization Hypervisor 3501 is also in communication with the non-SAN datastore 3503, the SAN datastore 3505 and the Copy Data Management Server 3509. The Copy Data Management Server 3509 is also in communication with SAN Datastore 3505, inband datastore 3506 and copy data storage 3508. FIG. 6 depicts Virtual disks 3546 and Managed Disks 3545.

In some embodiments, Copy Management Server 3509 probes all of the disks available to it and queries their unique IDs. In some embodiments, Copy Management Server 3509 can probe all of the Managed Disks 3545 that are mapped to it over the SAN, querying their SCSI ID, and reading their disk labels. If Copy Management Server 3509 determines that one of the Managed Disks 3545 is the same as the disk that makes up the datastore 3505 that is to be protected, it can create a Virtual Disk 3546 that is an image mapped version of the Managed disk 3545. Copy Management Server 3509 can create Virtual Disk 3546 with caching disabled so that every block of data is read directly from the managed disk. This ensures that the data that is backed up is current, and not stale data from the cache of Copy Management Server 3509.

FIG. 7 shows a flowchart of the LAN free backup of the SAN based LUN, according to some embodiments of the present disclosure.

With reference to FIGS. 3-6, for example, at the start of the backup, in step 3520, Copy Management Server 3509 creates a snapshot of the Virtual Machine to be backed up. This step provides a stable point in time image to back up.

Next, in step 3521, Copy Management Server 3509 uses the vendor's application programming interface to obtain unique IDs (e.g., LUN IDs, SCSI IDs, and disk labels) of the disks that make up the datastores of the virtual machine. For example, the unique ID can be a disk label or other ID that is written at the front of the disk to identify the disk. Such unique IDs are beneficial because they can identify the disk regardless of which path the disk is seen or accessed through. For example, one way of identifying a disk is by conveying which disk it is on a particular controller (e.g., the first disk on the first controller). Instead, unique IDs such as labels can be written to the front of the disk so that multiple paths can access the disk (e.g., for redundancy) and identify the disk using the unique ID (e.g., rather than needing to map that the first disk on first controller is same as second disk on second controller, and so on). So a lot use a unique disk label on each disk so can uniquely ID the disk.

In some embodiments, datastore disks (e.g., 3503, 3505, 3506), whether they be SAN based or non-SAN based, are visible to Virtualization Hypervisor 3501. The hypervisor vendor can provide an Application programming interface that allows access to the disks through the hypervisor host. In step 3522 Copy Management Server 3509 queries all of the Managed disks 3545 that it can see across the SAN, to obtain their unique IDs (e.g., LUN IDs, SCSI IDs and disk labels).

In step 3523, Copy Management Server 3509 compares all of the SCSI IDs of the datastores to the SCSI IDs of the Managed Disks 3545. If no match is found, in 3524, Copy Management Server 3509 recognizes that a LAN Free Backup is not possible. In step 3525, Copy Management Server 3509 reads the data over the LAN, and completes the backup, going to step 3530 where it deletes the Virtual Machine snapshot, and completes the backup.

If a match is found in step 3523, Copy Management Server 3509 prepares for a LAN Free backup. In step 3526, Copy Management Server 3509 creates a Virtual disk 3546 that is an image of the Managed disk 3545 whose ID matches the datastore disk ID. In step 3527, Copy Management Server 3509 turns off the caching for the newly created Virtual disk 3546. In step 3528, the Copy Management Server 3509 opens for reading and reads the data from the Virtual disk 3546 over the SAN and writes it to Copy Data Storage pool 3508. In step 3530, Copy Management Server 3509 deletes the Virtual Machine snapshot and completes the backup.

In some embodiments, a safety policy is implemented to prevent accidental writing to the SAN datastore Implementing the safety policy can include comparing the unique ID of any disk being opened for writing by the computing device against the unique IDs of all datastore disks (e.g., datastore disks presented by the SAN) to ascertain that the disk is not a datastore disk. The opening process is rejected if a match is found. Implementing the safety policy can also include examining the contents of the disk being opened for the signature pattern of a datastore. The opening process is rejected if a match is found.

For example, once a disk is exposed to the copy data store, there can be a risk that the copy data management server accidentally writes to the disk (e.g., because there is some software problem, or a program can trigger the copy data management server and ask to use the disk for something). Therefore the safety policy serves as a security layer before being able to write to any disk (e.g., before opening the disk for writing). The safety policy verifies that the disk is not a data store by looking at the pattern of data on the disk. For example, if a disk contains a data store there is often a particular structure and/or values on the disk (e.g., the first two blocks identify what type of data store and the version of the data store). If a disk has such a pattern, the system can determine that the disk is a data store and can prevent writing to the disk.

The subject matter described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. The subject matter described herein can be implemented as one or more computer program products, such as one or more computer programs tangibly embodied in an information carrier (e.g., in a machine readable storage device), or embodied in a propagated signal, for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). A computer program (also known as a program, software, software application, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file. A program can be stored in a portion of a file that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this specification, including the method steps of the subject matter described herein, can be performed by one or more programmable processors executing one or more computer programs to perform functions of the subject matter described herein by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus of the subject matter described herein can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processor of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of nonvolatile memory, including by way of example semiconductor memory devices, (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks, (e.g., internal hard disks or removable disks); magneto optical disks; and optical disks (e.g., CD and DVD disks). The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, (e.g., a mouse or a trackball), by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, (e.g., visual feedback, auditory feedback, or tactile feedback), and input from the user can be received in any form, including acoustic, speech, or tactile input.

The subject matter described herein can be implemented in a computing system that includes a back end component (e.g., a data server), a middleware component (e.g., an application server), or a front end component (e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described herein), or any combination of such back end, middleware, and front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

It is to be understood that the disclosed subject matter is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the disclosed subject matter. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the disclosed subject matter.

Although the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the disclosed subject matter may be made without departing from the spirit and scope of the disclosed subject matter. 

We claim:
 1. A computerized method of backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN), the method comprising: receiving, by a computing device, a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID; comparing, by the computing device, the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device; determining, by the computing device, the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device; opening for reading, by the computing device, the disk on the computing device with the matching unique ID; and copying, by the computing device, data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN).
 2. The computerized method of claim 1, further comprising: determining that the unique ID associated with the VM datastore disk does not match the unique ID associated with the disk on the computing device; and copying data from the VM to a copy data storage pool over a local area network.
 3. The computerized method of claim 1, further comprising disabling caching for the disk which has the matching unique ID.
 4. The computerized method of claim 1, wherein the unique ID comprises a logical unit number (LUN) ID, a small computer system interface (SCSI) ID, or a disk label.
 5. The computerized method of claim 1, wherein the disk available on the computing device comprises a disk presented to the computing device by a SAN datastore.
 6. The computerized method of claim 5, wherein the computing device is connected to the SAN datastore by a fiber channel or an Internet Small Computer System Interface (iSCSI) SAN connection.
 7. The computerized method of claim 1, further comprising implementing a safety policy to prevent accidental writing to the SAN datastore.
 8. The computerized method of claim 7, wherein implementing the safety policy comprises: comparing a unique ID of a disk associated with a write operation by the computing device against a unique ID of a datastore disk associated with the SAN datastore; and cancelling the write operation when the unique ID of a disk associated with a write operation by the computing device matches the unique ID of the datastore disk associated with the SAN datastore.
 9. The computerized method of claim 7, wherein implementing the safety policy comprises: determining the contents of a disk associated with a write operation contain a signature pattern associated with the SAN datastore; and cancelling the write operation.
 10. A computing system for backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN), the computing system comprising: a processor; and a memory coupled to the processor and including computer-readable instructions that, when executed by the processor, cause the processor to: receive a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID; compare the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device; determine the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device; open the disk on the computing device with the matching unique ID; and copy data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN).
 11. The computing system of claim 10, wherein the computer-readable instructions cause the processor to: determine that the unique ID associated with the VM datastore disk does not match the unique ID associated with the disk on the computing device; and copy data from the VM to a copy data storage pool over a local area network.
 12. The computing system of claim 10, wherein the computer-readable instructions cause the processor to disable caching for the disk which has the matching unique ID.
 13. The computing system of claim 10, wherein the unique ID comprises a logical unit number (LUN) ID, a small computer system interface (SCSI) ID, or a disk label.
 14. The computing system of claim 10, wherein the disk available on the computing device comprises a disk presented to the computing device by a SAN datastore.
 15. The computing system of claim 14, wherein the computing device is connected to the SAN datastore by a fiber channel or an Internet Small Computer System Interface (iSCSI) SAN connection.
 16. The computing system of claim 10, wherein the computer-readable instructions cause the processor to implement a safety policy to prevent accidental writing to the SAN datastore.
 17. The computing system of claim 16, wherein implementing the safety policy comprises: comparing a unique ID of a disk associated with a write operation by the computing device against a unique ID of a datastore disk associated with the SAN datastore; and cancelling the write operation when the unique ID of a disk associated with a write operation by the computing device matches the unique ID of the datastore disk associated with the SAN datastore.
 18. The computing system of claim 16, wherein implementing the safety policy comprises: determining the contents of a disk associated with a write operation contain a signature pattern associated with the SAN datastore; and cancelling the write operation.
 19. A non-transitory computer readable medium having executable instructions operable to cause an apparatus to: receive a snapshot of a virtual machine (VM) corresponding to a request to back up data associated with the VM, the VM being associated with a VM datastore and a VM datastore disk, wherein the VM datastore disk is associated with a unique ID; compare the unique ID associated with the VM datastore disk with a unique ID associated with a disk available on the computing device; determine the unique ID associated with the VM datastore disk matches the unique ID associated with the disk on the computing device; open the disk on the computing device with the matching unique ID; and copy data from the opened disk to a copy data storage pool over a storage area network, thereby backing up data associated with storage area network (SAN) data stores connected to a backup device over a SAN such that the backup is performed without using a local area network (LAN). 